Journal of Fungi

22 pages, 3736 KiB

Open AccessReview

Austin-Type Meroterpenoids from Fungi Reported in the Last Five Decades: A Review

by Jia-Li He, Chang-Jing Chen, Yong-Hong Liu, Cheng-Hai Gao, Rui-Ping Wang, Wen-Fei Zhang and Meng Bai

J. Fungi 2024, 10(2), 162; https://doi.org/10.3390/jof10020162 - 19 Feb 2024

Cited by 2 | Viewed by 1631

Abstract

Austin was first isolated as a novel polyisoprenoid mycotoxin from Aspergillus ustus in 1976. Subsequently, some new austin-type meroterpenoids (ATMTs) have been continually found. This review attempts to give a comprehensive summary of progress on the isolation, chemical structural features, biological activities, and [...] Read more.

Austin was first isolated as a novel polyisoprenoid mycotoxin from Aspergillus ustus in 1976. Subsequently, some new austin-type meroterpenoids (ATMTs) have been continually found. This review attempts to give a comprehensive summary of progress on the isolation, chemical structural features, biological activities, and fungal biodiversity of 104 novel ATMTs from 5 genera of terrestrial- and marine-derived fungi reported from October 1976 to January 2023. The genera of Penicillium and Aspergillus are the two dominant producers, producing 63.5% and 30.8% of ATMTs, respectively. Moreover, about 26.9% of ATMTs display various pronounced bioactivities, including insecticidal, anti-inflammatory, cytotoxicity, antibacterial, and PTP1B inhibitory activities. The chemical diversity and potential activities of these novel fungal ATMTs are reviewed for a better understanding, and a relevant summary focusing on the source fungi and their taxonomy is provided to shed light on the future development and research of austin-type meroterpenoids. Full article

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18 pages, 6259 KiB

Open AccessArticle

Identification and Aggressiveness of Fusarium Species Associated with Onion Bulb (Allium cepa L.) during Storage

by Roderic Gilles Claret Diabankana, Mikhail Frolov, Bakhtiyar Islamov, Elena Shulga, Maria Nikolaevna Filimonova, Daniel Mawuena Afordoanyi and Shamil Validov

J. Fungi 2024, 10(2), 161; https://doi.org/10.3390/jof10020161 - 19 Feb 2024

Viewed by 1921

Abstract

Plant pathogens present a major challenge to crop production, leading to decreased yield and quality during growth and storage. During long-term storage, healthy onions can develop diseases from latent pathogen infections. This poses a challenge for onion growers because infected bulbs without visible [...] Read more.

Plant pathogens present a major challenge to crop production, leading to decreased yield and quality during growth and storage. During long-term storage, healthy onions can develop diseases from latent pathogen infections. This poses a challenge for onion growers because infected bulbs without visible symptoms can lead to significant crop losses during the growing season. In this study, we aimed to isolate and identify Fusarium species from yellow onion bulbs (Allium cepa L.) that developed disease symptoms during storage. The aggressiveness of these strains against onion bulbs and seedlings was also evaluated. The isolated strains were further subjected to morphological and molecular differentiation. The results revealed that all 16 isolated strains belonged to the Fusarium complex species incarnatum-equiseti and Fusarium fujikuroi, namely, F. proliferatum (98%), F. oxysporum (1%), and Fusarium sp. (1%). Koch’s postulate analysis of isolated strains revealed varying aggressiveness on onion bulbs and plants depending on fungal species. Disease symptoms developed more slowly on plants than on onion bulb plants according to Koch’s postulates. Moreover, the results revealed that Fusarium strains that can infect onion plants were less pathogenic to onion bulbs and vice versa. In addition, three isolates were found to be non-pathogenic to onions. Furthermore, the in vitro control of Fusarium species through Bacillus velezensis KS04-AU and Streptomyces albidoflavus MGMM6 showed high potential for controlling the growth of these pathogenic fungi. These results may contribute to the development of environmentally friendly approaches for controlling onion spoilage caused by pathogens during storage. Full article

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16 pages, 1899 KiB

Open AccessArticle

Design, Synthesis, and Antifungal/Anti-Oomycete Activities of Novel 1,2,4-Triazole Derivatives Containing Carboxamide Fragments

by Jiali Wang, Haoran Shi and Aidang Lu

J. Fungi 2024, 10(2), 160; https://doi.org/10.3390/jof10020160 - 19 Feb 2024

Cited by 2 | Viewed by 1643

Abstract

Plant diseases caused by pathogenic fungi or oomycetes seriously affect crop growth and the quality and yield of products. A series of novel 1,2,4-triazole derivatives containing carboxamide fragments based on amide fragments widely used in fungicides and the commercialized mefentrifluconazole were designed and [...] Read more.

Plant diseases caused by pathogenic fungi or oomycetes seriously affect crop growth and the quality and yield of products. A series of novel 1,2,4-triazole derivatives containing carboxamide fragments based on amide fragments widely used in fungicides and the commercialized mefentrifluconazole were designed and synthesized. Their antifungal activities were evaluated against seven kinds of phytopathogenic fungi/oomycete. Results showed that most compounds had similar or better antifungal activities compared to mefentrifluconazole’s inhibitory activity against Physalospora piricola, especially compound 6h (92%), which possessed outstanding activity. Compound 6h (EC₅₀ = 13.095 μg/mL) showed a better effect than that of mefentrifluconazole (EC₅₀ = 39.516 μg/mL). Compound 5j (90%) displayed outstanding anti-oomycete activity against Phytophthora capsici, with an EC₅₀ value of 17.362 μg/mL, far superior to that of mefentrifluconazole (EC₅₀ = 75.433 μg/mL). The result of molecular docking showed that compounds 5j and 6h possessed a stronger affinity for 14α-demethylase (CYP51). This study provides a new approach to expanding the fungicidal spectrum of 1,2,4-triazole derivatives. Full article

(This article belongs to the Special Issue Plant Protection: New Green Antifungal Agents)

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11 pages, 3110 KiB

Open AccessCommunication

Identification of Chromoblastomycosis and Phaeohyphomycosis Agents through ITS-RFLP

by Gabriel S. M. Sousa, Rodrigo S. De Oliveira, Alex B. De Souza, Ruan C. Monteiro, Elaine P. T. E. Santo, Luciano C. Franco Filho and Silvia H. M. Da Silva

J. Fungi 2024, 10(2), 159; https://doi.org/10.3390/jof10020159 - 18 Feb 2024

Cited by 2 | Viewed by 1564

Abstract

Chromoblastomycosis (CBM) and phaeohyphomycosis (FEO) are infections caused by melanized filamentous fungal agents, primarily found in tropical and subtropical regions. Both infections pose significant challenges for the correct identification of the causative agent due to their morphological similarity, making conventional methods of morphological [...] Read more.

Chromoblastomycosis (CBM) and phaeohyphomycosis (FEO) are infections caused by melanized filamentous fungal agents, primarily found in tropical and subtropical regions. Both infections pose significant challenges for the correct identification of the causative agent due to their morphological similarity, making conventional methods of morphological analysis highly subjective. Therefore, molecular techniques are necessary for the precise determination of these species. In this regard, this study aimed to contribute to a new methodology based on PCR-RFLP for the identification of agents causing CBM and FEO. Sequences from the Internal Transcribed Spacer (ITS) region were used to identify potential restriction enzyme sites in silico, followed by in vitro validation using the selected restriction enzymes. The obtained results were compared with species identification through morphological analyses and sequencing. The results demonstrated that the PCR-RFLP applied in this study accurately identified two major agents of chromoblastomycosis, Fonsecaea pedrosoi and Fonsecaea monophora, as well as Cladophialophora bantiana and Exophiala dermatitidis, both causative agents of phaeohyphomycosis. In this context, the proposed assay can complement current methods for identifying these species, aiding in diagnosis, and contributing to the proper management of these infections. Full article

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19 pages, 9061 KiB

Open AccessArticle

A New Biocontrol Agent Bacillus velezensis SF334 against Rubber Tree Fungal Leaf Anthracnose and Its Genome Analysis of Versatile Plant Probiotic Traits

by Muyuan Wang, Yikun Zhang, Haibin Cai, Xinyang Zhao, Zhongfeng Zhu, Yichao Yan, Ke Yin, Guanyun Cheng, Yinsheng Li, Gongyou Chen, Lifang Zou and Min Tu

J. Fungi 2024, 10(2), 158; https://doi.org/10.3390/jof10020158 - 17 Feb 2024

Cited by 1 | Viewed by 1747

Abstract

Natural rubber is an important national strategic and industrial raw material. The leaf anthracnose of rubber trees caused by the Colletotrichum species is one of the important factors restricting the yields of natural rubber. In this study, we isolated and identified strain Bacillus [...] Read more.

Natural rubber is an important national strategic and industrial raw material. The leaf anthracnose of rubber trees caused by the Colletotrichum species is one of the important factors restricting the yields of natural rubber. In this study, we isolated and identified strain Bacillus velezensis SF334, which exhibited significant antagonistic activity against both C. australisinense and C. siamense, the dominant species of Colletotrichum causing rubber tree leaf anthracnose in the Hainan province of China, from a pool of 223 bacterial strains. The cell suspensions of SF334 had a significant prevention effect for the leaf anthracnose of rubber trees, with an efficacy of 79.67% against C. siamense and 71.8% against C. australisinense. We demonstrated that SF334 can lead to the lysis of C. australisinense and C. siamense mycelia by causing mycelial expansion, resulting in mycelial rupture and subsequent death. B. velezensis SF334 also harbors some plant probiotic traits, such as secreting siderophore, protease, cellulase, pectinase, and the auxin of indole-3-acetic acid (IAA), and it has broad-spectrum antifungal activity against some important plant pathogenic fungi. The genome combined with comparative genomic analyses indicated that SF334 possesses most genes of the central metabolic and gene clusters of secondary metabolites in B. velezensis strains. To our knowledge, this is the first time a Bacillus velezensis strain has been reported as a promising biocontrol agent against the leaf anthracnose of rubber trees caused by C. siamense and C. australisinense. The results suggest that B. velezensis could be a potential candidate agent for the leaf anthracnose of rubber trees. Full article

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16 pages, 2013 KiB

Open AccessArticle

Expanding the Toolbox for Genetic Manipulation in Pseudogymnoascus: RNAi-Mediated Silencing and CRISPR/Cas9-Mediated Disruption of a Polyketide Synthase Gene Involved in Red Pigment Production in P. verrucosus

by Diego Palma, Vicente Oliva, Mariana Montanares, Carlos Gil-Durán, Dante Travisany, Renato Chávez and Inmaculada Vaca

J. Fungi 2024, 10(2), 157; https://doi.org/10.3390/jof10020157 - 16 Feb 2024

Viewed by 1974

Abstract

Fungi belonging to the genus Pseudogymnoascus have garnered increasing attention in recent years. One of the members of the genus, P. destructans, has been identified as the causal agent of a severe bat disease. Simultaneously, the knowledge of Pseudogymnoascus species has expanded, [...] Read more.

Fungi belonging to the genus Pseudogymnoascus have garnered increasing attention in recent years. One of the members of the genus, P. destructans, has been identified as the causal agent of a severe bat disease. Simultaneously, the knowledge of Pseudogymnoascus species has expanded, in parallel with the increased availability of genome sequences. Moreover, Pseudogymnoascus exhibits great potential as a producer of specialized metabolites, displaying a diverse array of biological activities. Despite these significant advancements, the genetic landscape of Pseudogymnoascus remains largely unexplored due to the scarcity of suitable molecular tools for genetic manipulation. In this study, we successfully implemented RNAi-mediated gene silencing and CRISPR/Cas9-mediated disruption in Pseudogymnoascus, using an Antarctic strain of Pseudogymnoascus verrucosus as a model. Both methods were applied to target azpA, a gene involved in red pigment biosynthesis. Silencing of the azpA gene to levels of 90% or higher eliminated red pigment production, resulting in transformants exhibiting a white phenotype. On the other hand, the CRISPR/Cas9 system led to a high percentage (73%) of transformants with a one-nucleotide insertion, thereby inactivating azpA and abolishing red pigment production, resulting in a white phenotype. The successful application of RNAi-mediated gene silencing and CRISPR/Cas9-mediated disruption represents a significant advancement in Pseudogymnoascus research, opening avenues for comprehensive functional genetic investigations within this underexplored fungal genus. Full article

(This article belongs to the Special Issue Recent Advances in Fungal Secondary Metabolism, 2nd Edition)

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14 pages, 23526 KiB

Open AccessArticle

Identification and Characterization of Nigrospora Species and a Novel Species, Nigrospora anhuiensis, Causing Black Leaf Spot on Rice and Wild Rice in the Anhui Province of China

by Yang Liu, Jiahao An, Asma Safdar, Yang Shen, Yang Sun, Wenhui Shu, Xiaojuan Tan, Bo Zhu, Jiaxin Xiao, Jan Schirawski, Feng He and Guoping Zhu

J. Fungi 2024, 10(2), 156; https://doi.org/10.3390/jof10020156 - 16 Feb 2024

Cited by 1 | Viewed by 2406

Abstract

Rice production in the Anhui province is threatened by fungal diseases. We obtained twenty-five fungal isolates from rice and wild rice leaves showing leaf spot disease collected along the Yangtze River. A phylogenetic analysis based on internal transcribed spacer (ITS), translation elongation factor [...] Read more.

Rice production in the Anhui province is threatened by fungal diseases. We obtained twenty-five fungal isolates from rice and wild rice leaves showing leaf spot disease collected along the Yangtze River. A phylogenetic analysis based on internal transcribed spacer (ITS), translation elongation factor 1 alpha (TEF1-α), and beta tubulin (TUB2) sequences revealed one isolate (SS-2-JB-1B) grouped with Nigrospora sphaerica, one (QY) with Nigrospora chinensis, twenty-two with Nigrospora oryzae, and one isolate (QY-2) grouped in its own clade, which are related to but clearly different from N. oryzae. Nineteen tested isolates, including sixteen strains from the N. oryzae clade and the three isolates of the other three clades, caused disease on detached rice leaves. The three isolates that did not belong to N. oryzae were also able to cause disease in rice seedlings, suggesting that they were rice pathogens. Isolate QY-2 differed from the other isolates in terms of colony morphology, cell size, and susceptibility to fungicides, indicating that this isolate represents a new species that we named Nigrospora anhuiensis. Our analysis showed that N. sphaerica, N. chinensis, and the new species, N. anhuiensis, can cause rice leaf spot disease in the field. This research provides new knowledge for understanding rice leaf spot disease. Full article

(This article belongs to the Special Issue Interactions between Filamentous Fungal Pathogens and Hosts: 2nd Edition)

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16 pages, 814 KiB

Open AccessReview

Nitric Oxide in Fungi: Production and Function

by Nan-Nan Yu and Gyungsoon Park

J. Fungi 2024, 10(2), 155; https://doi.org/10.3390/jof10020155 - 15 Feb 2024

Cited by 1 | Viewed by 1911

Abstract

Nitric oxide (NO) is synthesized in all kingdoms of life, where it plays a role in the regulation of various physiological and developmental processes. In terms of endogenous NO biology, fungi have been less well researched than mammals, plants, and bacteria. In this [...] Read more.

Nitric oxide (NO) is synthesized in all kingdoms of life, where it plays a role in the regulation of various physiological and developmental processes. In terms of endogenous NO biology, fungi have been less well researched than mammals, plants, and bacteria. In this review, we summarize and discuss the studies to date on intracellular NO biosynthesis and function in fungi. Two mechanisms for NO biosynthesis, NO synthase (NOS)-mediated arginine oxidation and nitrate- and nitrite-reductase-mediated nitrite reduction, are the most frequently reported. Furthermore, we summarize the multifaceted functions of NO in fungi as well as its role as a signaling molecule in fungal growth regulation, development, abiotic stress, virulence regulation, and metabolism. Finally, we present potential directions for future research on fungal NO biology. Full article

(This article belongs to the Section Fungal Genomics, Genetics and Molecular Biology)

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12 pages, 1784 KiB

Open AccessReview

Processes Controlling the Contractile Ring during Cytokinesis in Fission Yeast, Including the Role of ESCRT Proteins

by Imane M. Rezig, Wandiahyel G. Yaduma and Christopher J. McInerny

J. Fungi 2024, 10(2), 154; https://doi.org/10.3390/jof10020154 - 15 Feb 2024

Viewed by 1859

Abstract

Cytokinesis, as the last stage of the cell division cycle, is a tightly controlled process amongst all eukaryotes, with defective division leading to severe cellular consequences and implicated in serious human diseases and conditions such as cancer. Both mammalian cells and the fission [...] Read more.

Cytokinesis, as the last stage of the cell division cycle, is a tightly controlled process amongst all eukaryotes, with defective division leading to severe cellular consequences and implicated in serious human diseases and conditions such as cancer. Both mammalian cells and the fission yeast Schizosaccharomyces pombe use binary fission to divide into two equally sized daughter cells. Similar to mammalian cells, in S. pombe, cytokinetic division is driven by the assembly of an actomyosin contractile ring (ACR) at the cell equator between the two cell tips. The ACR is composed of a complex network of membrane scaffold proteins, actin filaments, myosin motors and other cytokinesis regulators. The contraction of the ACR leads to the formation of a cleavage furrow which is severed by the endosomal sorting complex required for transport (ESCRT) proteins, leading to the final cell separation during the last stage of cytokinesis, the abscission. This review describes recent findings defining the two phases of cytokinesis in S. pombe: ACR assembly and constriction, and their coordination with septation. In summary, we provide an overview of the current understanding of the mechanisms regulating ACR-mediated cytokinesis in S. pombe and emphasize a potential role of ESCRT proteins in this process. Full article

(This article belongs to the Special Issue Yeast Cytokinesis)

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14 pages, 951 KiB

Open AccessReview

Medicinal Mushrooms as Multicomponent Mixtures—Demonstrated with the Example of Lentinula edodes

by Ulrike Lindequist

J. Fungi 2024, 10(2), 153; https://doi.org/10.3390/jof10020153 - 15 Feb 2024

Cited by 2 | Viewed by 2410

Abstract

Medicinal mushrooms are multicomponent mixtures (MOCSs). They consist of a large number of individual compounds, each with different chemical structures, functions, and possible pharmacological activities. In contrast to the activity of an isolated pure substance, the effects of the individual substances in a [...] Read more.

Medicinal mushrooms are multicomponent mixtures (MOCSs). They consist of a large number of individual compounds, each with different chemical structures, functions, and possible pharmacological activities. In contrast to the activity of an isolated pure substance, the effects of the individual substances in a mushroom or its extracts can influence each other; they can strengthen, weaken, or complement each other. This results in both advantages and disadvantages for the use of either a pure substance or a multicomponent mixture. The review describes the differences and challenges in the preparation, characterization, and application of complex mixtures compared to pure substances, both obtained from the same species. As an example, we use the medicinal and culinary mushroom Lentinula edodes, shiitake, and some of its isolated compounds, mainly lentinan and eritadenine. Full article

(This article belongs to the Special Issue Current and Future Research Trends on Medicinal Mushrooms)

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24 pages, 1732 KiB

Open AccessArticle

Influence of Salinity on the Extracellular Enzymatic Activities of Marine Pelagic Fungi

by Katherine Salazar-Alekseyeva, Gerhard J. Herndl and Federico Baltar

J. Fungi 2024, 10(2), 152; https://doi.org/10.3390/jof10020152 - 13 Feb 2024

Cited by 1 | Viewed by 2145

Abstract

Even though fungi are ubiquitous in the biosphere, the ecological knowledge of marine fungi remains rather rudimentary. Also, little is known about their tolerance to salinity and how it influences their activities. Extracellular enzymatic activities (EEAs) are widely used to determine heterotrophic microbes’ [...] Read more.

Even though fungi are ubiquitous in the biosphere, the ecological knowledge of marine fungi remains rather rudimentary. Also, little is known about their tolerance to salinity and how it influences their activities. Extracellular enzymatic activities (EEAs) are widely used to determine heterotrophic microbes’ enzymatic capabilities and substrate preferences. Five marine fungal species belonging to the most abundant pelagic phyla (Ascomycota and Basidiomycota) were grown under non-saline and saline conditions (0 g/L and 35 g/L, respectively). Due to their sensitivity and specificity, fluorogenic substrate analogues were used to determine hydrolytic activity on carbohydrates (β-glucosidase, β-xylosidase, and N-acetyl-β-D-glucosaminidase); peptides (leucine aminopeptidase and trypsin); lipids (lipase); organic phosphorus (alkaline phosphatase), and sulfur compounds (sulfatase). Afterwards, kinetic parameters such as maximum velocity (V_max) and half-saturation constant (K_m) were calculated. All fungal species investigated cleaved these substrates, but some species were more efficient than others. Moreover, most enzymatic activities were reduced in the saline medium, with some exceptions like sulfatase. In non-saline conditions, the average V_max ranged between 208.5 to 0.02 μmol/g biomass/h, and in saline conditions, 88.4 to 0.02 μmol/g biomass/h. The average K_m ranged between 1553.2 and 0.02 μM with no clear influence of salinity. Taken together, our results highlight a potential tolerance of marine fungi to freshwater conditions and indicate that changes in salinity (due to freshwater input or evaporation) might impact their enzymatic activities spectrum and, therefore, their contribution to the oceanic elemental cycles. Full article

(This article belongs to the Special Issue Halotolerant and Halophilic Fungi)

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15 pages, 4248 KiB

Open AccessArticle

Inhibitory Effect of L-Methionine on Alternaria alternata Based on Metabolomics Analysis

by Xianran Zhu, Shaoying Zhang, Youwei Yu, Shengwang Li, Chao Yang and Yuan Chang

J. Fungi 2024, 10(2), 151; https://doi.org/10.3390/jof10020151 - 13 Feb 2024

Cited by 2 | Viewed by 1550

Abstract

Alternaria alternata is the main pathogenic fungus of postharvest black spots in fruits and vegetables. This study aimed to explore the antifungal activity of methionine on A. alternata in vitro and to reveal related antifungal mechanisms through a metabolomics analysis. The results showed [...] Read more.

Alternaria alternata is the main pathogenic fungus of postharvest black spots in fruits and vegetables. This study aimed to explore the antifungal activity of methionine on A. alternata in vitro and to reveal related antifungal mechanisms through a metabolomics analysis. The results showed that the inhibitory effects of L-methionine (Met) treatment on mycelium growth, spore germination, and the germ tube elongation of A. alternata were enhanced with an increase in the Met concentration, but the inhibitory effects decreased when the Met concentration was higher than 50 mmolL⁻¹. The results of propidium iodide staining and scanning electron microscopy showed that the Met treatment damaged the plasma membrane integrity of the A. alternata spores and caused an irreversible deformation of mycelium. In addition, after the Met treatment, the leakage of electrolytes, nucleic acid, and proteins in the A. alternata cells was significantly higher than that in the control group, indicating that the Met treatment increased the permeability of the cell membranes. Eighty-one different metabolites, divided into seven categories, were identified through the metabolomics analysis, including forty-three downregulated metabolites and thirty-eight upregulated metabolites. Among them, these differential metabolites were mainly involved in amino acid synthesis and metabolism, the pentose phosphate pathway, and the TCA cycle. Therefore, the antifungal effect of the Met treatment on A. alternata was mainly to damage the integrity of the cell membranes, make nucleic acid and protein contents leak, and affect the TCA cycle, carbohydrate metabolism, amino acid synthesis metabolism, and the metabolic pathways associated with cell membrane biosynthesis. Thus, the growth and development of A. alternata were inhibited. The research enriched the investigation of the effect of the antifungal mechanism of Met treatment on A. alternata and provided a theoretical basis for the application of Met to prevent and treat postharvest black spots in fruits and vegetables. Full article

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14 pages, 3001 KiB

Open AccessArticle

The Stress of Fungicides Changes the Expression of Clock Protein CmFRQ and the Morphology of Fruiting Bodies of Cordyceps militaris

by Jing-Mei Peng, Dan-Dan Zhang, Zi-Yan Huang and Ming-Jia Fu

J. Fungi 2024, 10(2), 150; https://doi.org/10.3390/jof10020150 - 13 Feb 2024

Viewed by 1418

Abstract

The physiological, biochemical, and morphological changes brought about by fungi in response to fungicides can undoubtedly bring diversity to fungi. Cordyceps militaris strains TN (mating type genes MAT1-1-1, MAT1-1-2, and MAT1-2-1) and CmFRQ-454 (mating type genes MAT1-1-1 and MAT1-1-2) [...] Read more.

The physiological, biochemical, and morphological changes brought about by fungi in response to fungicides can undoubtedly bring diversity to fungi. Cordyceps militaris strains TN (mating type genes MAT1-1-1, MAT1-1-2, and MAT1-2-1) and CmFRQ-454 (mating type genes MAT1-1-1 and MAT1-1-2) were treated with non-lethal doses of fungicides amphotericin B, L-cysteine, terbinafine, and 5-fluorocytosine. The results showed that the treatment with amphotericin B, terbinafine, and 5-fluorocytosine promoted an increase in the relative content of clock protein CmFRQ (C. militaris FREQUENCY) in the mycelium of strain TN, while the high concentration of L-cysteine inhibited the expression of CmFRQ in strain TN. These four fungicides could reduce the relative contents of CmFRQ in the mycelium of strain CmFRQ454. The relative contents of CmFRQ in the mycelium of strain TN were increased after removing the four fungicides, but the relative contents of CmFRQ in the mycelium of strain CmFRQ454 were decreased after removing the four fungicides. This indicates that the effect of fungicides on CmFRQ on mycelium was still sustained after removing the stress of fungicides, and the operation of the circadian clock was changed. The fruiting bodies of C. militaris strain TN and CmFRQ-454 were still degenerated to varying degrees after removing amphotericin B, L-cysteine, and terbinafine. However, the fruiting bodies of strain TN after removing 5-fluorocytosine did not show significant degeneration; the fruiting bodies of strain CmFRQ-454 after removing 5-fluorocytosine obtained rejuvenation. These results indicate that the stress of fungicides could lead to the degeneration of fruiting bodies as well as the rejuvenation of fruiting bodies, resulting in the morphological diversity of C. militaris. The increase or decrease of the CmFRQ-454, the main component of the circadian clock, caused by the stress of fungicants, might lead to the differential degeneration of different mating-type strains of C. militaris. Full article

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13 pages, 3080 KiB

Open AccessArticle

Clinical Diagnosis and Laboratory Testing of Abnormal Appearing Toenails: A Retrospective Assessment of Confirmatory Testing for Onychomycosis in the United States, 2022–2023

by Aditya K. Gupta, Tong Wang, Elizabeth A. Cooper, Sara A. Lincoln, Hui-Chen Foreman, William P. Scherer and Wayne L. Bakotic

J. Fungi 2024, 10(2), 149; https://doi.org/10.3390/jof10020149 - 13 Feb 2024

Cited by 5 | Viewed by 2618

Abstract

Onychomycosis is an under-recognized healthcare burden. Despite the risk of misdiagnosis, confirmatory laboratory testing is under-utilized. Histopathologic examination with polymerase chain reaction (PCR) is currently the most effective diagnostic method; it offers direct detection and identification of a fungal invasion. In this retrospective [...] Read more.

Onychomycosis is an under-recognized healthcare burden. Despite the risk of misdiagnosis, confirmatory laboratory testing is under-utilized. Histopathologic examination with polymerase chain reaction (PCR) is currently the most effective diagnostic method; it offers direct detection and identification of a fungal invasion. In this retrospective cohort study, we assessed confirmatory testing results, with matching clinical diagnoses, in 96,293 nail specimens submitted during a 9-month period from 2022 to 2023. Toenail specimens were examined using fungal culture, histopathology and/or PCR. Clinical diagnoses were identified using the International Classification of Diseases 10th Revision codes. For clinically diagnosed onychomycosis patients, the overall positivity rate was 59.4%; a similar positivity rate (59.5%) was found in patients with clinically diagnosed non-fungal nail dystrophy. Performing a histopathologic examination with PCR was more likely to provide pathogen identification results than using fungal culture. Male patients had a higher rate of onychomycosis overall; however, female patients had more non-dermatophyte mold onychomycosis caused by Aspergillus. Clinically diagnosed onychomycosis patients with a co-diagnosis of tinea pedis were more likely to test positive for onychomycosis by PCR (odds ratio [OR]: 4.2; 95% confidence interval [CI]: 2.7–6.4), histopathology (OR: 2.5; 95% CI: 2.0–3.1) and fungal culture (OR: 3.2; 95% CI: 1.5–6.6). Our results support the use of confirmatory laboratory testing when there is a clinical diagnosis of onychomycosis. Full article

(This article belongs to the Special Issue New Perspectives for Superficial Fungal Infections, Second Edition)

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11 pages, 1440 KiB

Open AccessArticle

Antifungal Effect of Metabolites from Bacterial Symbionts of Entomopathogenic Nematodes on Fusarium Head Blight of Wheat

by Julius Leumo Kgosiemang, Tshimangadzo Ramakuwela, Sandiswa Figlan and Nicolene Cochrane

J. Fungi 2024, 10(2), 148; https://doi.org/10.3390/jof10020148 - 12 Feb 2024

Viewed by 1669

Abstract

Fungal diseases such as Fusarium head blight (FHB) are significant biotic stressors, negatively affecting wheat production and quality. This study explored the antifungal activity of the metabolites produced by the bacterial symbionts of entomopathogenic nematodes (EPNs) against FHB-causing Fusarium sp. Fusarium graminearum. [...] Read more.

Fungal diseases such as Fusarium head blight (FHB) are significant biotic stressors, negatively affecting wheat production and quality. This study explored the antifungal activity of the metabolites produced by the bacterial symbionts of entomopathogenic nematodes (EPNs) against FHB-causing Fusarium sp. Fusarium graminearum. To achieve this, the symbiotic bacteria of nine EPN isolates from the EPN collection at the Agricultural Research Council-Small Grains (ARC-SG) were isolated from the cadavers of Galleria mellonella (Lepidoptera: Pyralidae) larvae after infection with EPNs. Broth cultures (crude) and their supernatants (filtered and autoclaved) of each bacterial isolate were used as bacterial metabolite treatments to test their inhibitory effect on the mycelial growth and spore germination of F. graminearum. Mycelial growth inhibition rates varied among both bacterial isolates and treatments. Crude metabolite treatments proved to be more effective than filtered and autoclaved metabolite treatments, with an overall inhibition rate of 75.25% compared to 23.93% and 13.32%, respectively. From the crude metabolite treatments, the Xenorhabdus khoisanae SGI 197 bacterial isolate from Steinernema beitlechemi SGI 197 had the highest mean inhibition rate of 96.25%, followed by Photorhabdus luminescens SGI 170 bacteria isolated from Heterorhabditis bacteriophora SGI 170 with a 95.79% mean inhibition rate. The filtered metabolite treatments of all bacterial isolates were tested for their inhibitory activity against Fusarium graminearum spore germination. Mean spore germination inhibition rates from Xenorhabdus spp. bacterial isolates were higher (83.91 to 96.29%) than those from Photorhabdus spp. (6.05 to 14.74%). The results obtained from this study suggest that EPN symbiotic bacterial metabolites have potential use as biological control agents of FHB. Although field efficacy against FHB was not studied, the significant inhibition of mycelial growth and spore germination suggest that the application of these metabolites at the flowering stage may provide protection to plants against infection with or spread of F. graminearum. These metabolites have the potential to be employed as part of integrated pest management (IPM) to inhibit/delay conidia germination until the anthesis (flowering stage) of wheat seedlings has passed. Full article

(This article belongs to the Special Issue Fusarium spp.: A Trans-Kingdom Fungus)

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13 pages, 1825 KiB

Open AccessArticle

Rapid Classification of Serum from Patients with Paracoccidioidomycosis Using Infrared Spectroscopy, Univariate Statistics, and Linear Discriminant Analysis (LDA)

by Alessandra Koehler, Maria Lúcia Scroferneker, Nikolas Mateus Pereira de Souza, Paulo Cezar de Moraes, Beatriz Aparecida Soares Pereira, Ricardo de Souza Cavalcante, Rinaldo Pôncio Mendes and Valeriano Antonio Corbellini

J. Fungi 2024, 10(2), 147; https://doi.org/10.3390/jof10020147 - 12 Feb 2024

Cited by 1 | Viewed by 1438

Abstract

Paracoccidioidomycosis (PCM) is a systemic mycosis that is diagnosed by visualizing the fungus in clinical samples or by other methods, like serological techniques. However, all PCM diagnostic methods have limitations. The aim of this study was to develop a diagnostic tool for PCM [...] Read more.

Paracoccidioidomycosis (PCM) is a systemic mycosis that is diagnosed by visualizing the fungus in clinical samples or by other methods, like serological techniques. However, all PCM diagnostic methods have limitations. The aim of this study was to develop a diagnostic tool for PCM based on Fourier transform infrared (FTIR) spectroscopy. A total of 224 serum samples were included: 132 from PCM patients and 92 constituting the control group (50 from healthy blood donors and 42 from patients with other systemic mycoses). Samples were analyzed by attenuated total reflection (ATR) and a t-test was performed to find differences in the spectra of the two groups. The wavenumbers that had p < 0.05 had their diagnostic potential evaluated using receiver operating characteristic (ROC) curves. The spectral region with the lowest p value was used for variable selection through principal component analysis (PCA). The selected variables were used in a linear discriminant analysis (LDA). In univariate analysis, the ROC curves with the best performance were obtained in the region 1551–1095 cm⁻¹. The wavenumber that had the highest AUC value was 1264 cm⁻¹, achieving a sensitivity of 97.73%, specificity of 76.01%, and accuracy of 94.22%. The total separation of groups was obtained in the PCA performed with a spectral range of 1551–1095 cm⁻¹. LDA performed with the eight wavenumbers with the greatest weight from the group discrimination in the PCA obtained 100% accuracy. The methodology proposed here is simple, fast, and highly accurate, proving its potential to be applied in the diagnosis of PCM. The proposed method is more accurate than the currently known diagnostic methods, which is particularly relevant for a neglected tropical mycosis such as paracoccidioidomycosis. Full article

(This article belongs to the Special Issue New Insights into Paracoccidioides and Paracoccidioidomycosis)

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32 pages, 3102 KiB

Open AccessReview

Preclinical Models for Cryptococcosis of the CNS and Their Characterization Using In Vivo Imaging Techniques

by Lara Roosen, Dries Maes, Luigi Musetta and Uwe Himmelreich

J. Fungi 2024, 10(2), 146; https://doi.org/10.3390/jof10020146 - 12 Feb 2024

Cited by 2 | Viewed by 2594

Abstract

Infections caused by Cryptococcus neoformans and Cryptococcus gattii remain a challenge to our healthcare systems as they are still difficult to treat. In order to improve treatment success, in particular for infections that have disseminated to the central nervous system, a better understanding [...] Read more.

Infections caused by Cryptococcus neoformans and Cryptococcus gattii remain a challenge to our healthcare systems as they are still difficult to treat. In order to improve treatment success, in particular for infections that have disseminated to the central nervous system, a better understanding of the disease is needed, addressing questions like how it evolves from a pulmonary to a brain disease and how novel treatment approaches can be developed and validated. This requires not only clinical research and research on the microorganisms in a laboratory environment but also preclinical models in order to study cryptococci in the host. We provide an overview of available preclinical models, with particular emphasis on models of cryptococcosis in rodents. In order to further improve the characterization of rodent models, in particular the dynamic aspects of disease manifestation, development, and ultimate treatment, preclinical in vivo imaging methods are increasingly used, mainly in research for oncological, neurological, and cardiac diseases. In vivo imaging applications for fungal infections are rather sparse. A second aspect of this review is how research on models of cryptococcosis can benefit from in vivo imaging methods that not only provide information on morphology and tissue structure but also on function, metabolism, and cellular properties in a non-invasive way. Full article

(This article belongs to the Special Issue Cryptococcus and Cryptococcosis 2.0)

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12 pages, 2285 KiB

Open AccessArticle

The Relationship between Endophytic Fungi of Chimonanthus praecox and Volatile Metabolites under Different Circadian Rhythms and Blooming Stages

by Yue Li, Jingying Hei, Xiahong He, Rui Rui and Shu Wang

J. Fungi 2024, 10(2), 145; https://doi.org/10.3390/jof10020145 - 11 Feb 2024

Viewed by 1654

Abstract

Chimonanthus praecox is an aromatic plant that flowers in winter. The composition of the floral volatiles of C. praecox is influenced by different blooming stages, circadian rhythms and species. However, the relationship between floral volatiles and plant endophytic fungi has not received much research [...] Read more.

Chimonanthus praecox is an aromatic plant that flowers in winter. The composition of the floral volatiles of C. praecox is influenced by different blooming stages, circadian rhythms and species. However, the relationship between floral volatiles and plant endophytic fungi has not received much research attention. Here, we used high-throughput sequencing technology to compare and analyze the changes in the structure and diversity of the endophytic fungal communities in C. praecox under different circadian rhythms (7:00 a.m., 1:00 p.m., and 7:00 p.m.) and in different blooming stages (unopened flowers and opened flowers). The endophytic fungi of C. praecox consisted of nine phyla, 34 classes, 79 orders, 181 families, 293 genera, and 397 species, and Ascomycota was the dominant phylum. Under a diurnal rhythm, the diversity (Chao1 and Shannon indices) of endophytic fungi gradually decreased in the unopened flowers, while an increasing and then decreasing trend was found for the opened flowers. In the different blooming stages, the endophytic fungal diversity was significantly higher at 7:00 a.m. in the unopened flowers compared to the opened flowers. Humidity was the key factors that significantly affected the endophytic fungal diversity and community. Moreover, 11 endophytic fungi were significantly positively or negatively correlated with seven floral volatiles. In conclusion, the community structure and diversity of endophytic fungi in C. praecox were affected by the different blooming stages and circadian rhythms, and a correlation effect related to floral volatiles was found, but there are other possible reasons that were not tested. This study provides a theoretical basis for elucidating the interrelationships between endophytic fungi, floral volatiles, and environmental factors in C. praecox. Full article

(This article belongs to the Special Issue Advances in Fungal Endophyte Research)

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24 pages, 2332 KiB

Open AccessReview

Biological Activities of Secondary Metabolites from the Edible-Medicinal Macrofungi

by Xiaoqi Sun, Ying Shi, Dongxiao Shi, Yu Tu and Ling Liu

J. Fungi 2024, 10(2), 144; https://doi.org/10.3390/jof10020144 - 11 Feb 2024

Cited by 3 | Viewed by 2371

Abstract

Macrofungi are well-known as edible-medicinal mushrooms, which belong mostly to Basidiomycota, with a few from Ascomycota. In recent years, macrofungi have been recognized as a rich resource of structurally unique secondary metabolites, demonstrating a wide range of bioactivities, including anti-tumor, antioxidant, anti-inflammatory, antimicrobial, [...] Read more.

Macrofungi are well-known as edible-medicinal mushrooms, which belong mostly to Basidiomycota, with a few from Ascomycota. In recent years, macrofungi have been recognized as a rich resource of structurally unique secondary metabolites, demonstrating a wide range of bioactivities, including anti-tumor, antioxidant, anti-inflammatory, antimicrobial, antimalarial, neuro-protective, hypoglycemic, and hypolipidemic activities. This review highlights over 270 natural products produced by 17 families of macrofungi covering 2017 to 2023, including their structures, bioactivities, and related molecular mechanisms. Full article

(This article belongs to the Special Issue Edible and Medicinal Macrofungi, 3rd Edition)

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15 pages, 7266 KiB

Open AccessArticle

Peroxin MoPex22 Regulates the Import of Peroxisomal Matrix Proteins and Appressorium-Mediated Plant Infection in Magnaporthe oryzae

by Rangrang Chen, Kailun Lu, Lina Yang, Jihong Jiang and Lianwei Li

J. Fungi 2024, 10(2), 143; https://doi.org/10.3390/jof10020143 - 10 Feb 2024

Cited by 1 | Viewed by 1594

Abstract

Magnaporthe oryzae, the pathogen responsible for rice blast disease, utilizes specialized infection structures known as appressoria to breach the leaf cuticle and establish intracellular, infectious hyphae. Our study demonstrates that the peroxin MoPex22 is crucial for appressorium function, specifically for the development [...] Read more.

Magnaporthe oryzae, the pathogen responsible for rice blast disease, utilizes specialized infection structures known as appressoria to breach the leaf cuticle and establish intracellular, infectious hyphae. Our study demonstrates that the peroxin MoPex22 is crucial for appressorium function, specifically for the development of primary penetration hyphae. The ∆Mopex22 mutant exhibited slow growth, reduced aerial hyphae, and almost complete loss of virulence. Specifically, despite the mutant’s capability to form appressoria, it showed abnormalities during appressorium development, including reduced turgor, increased permeability of the appressorium wall, failure to form septin rings, and significantly decreased ability to penetrate host cells. Additionally, there was a delay in the degradation of lipid droplets during conidial germination and appressorium development. Consistent with these findings, the ΔMopex22 mutant showed an inefficient utilization of long-chain fatty acids and defects in cell wall integrity. Moreover, our findings indicate that MoPex22 acts as an anchor for MoPex4, facilitating the localization of MoPex4 to peroxisomes. Together with MoPex4, it affects the function of MoPex5, thus regulating the import of peroxisomal matrix proteins. Overall, these results highlight the essential role of MoPex22 in regulating the transport of peroxisomal matrix proteins, which affect fatty acid metabolism, glycerol accumulation, cell wall integrity, growth, appressorium development, and the pathogenicity of M. oryzae. This study provides valuable insights into the significance of peroxin functions in fungal biology and appressorium-mediated plant infection. Full article

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4 pages, 223 KiB

Open AccessEditorial

Multifaceted Beauveria bassiana and Other Insect-Related Fungi

by Nicolás Pedrini, Éverton K. K. Fernandes and Ivan M. Dubovskiy

J. Fungi 2024, 10(2), 142; https://doi.org/10.3390/jof10020142 - 9 Feb 2024

Viewed by 1933

Abstract

Since Agostino Bassi first isolated the fungal pathogenic agent of the white muscardine in insects (later named Beauveria bassiana in his honor), and Ilya Mechnikov cultivated Metarhizium anisopliae as a first approach to use fungi as pest control agents, many other entomopathogenic fungi [...] Read more.

Since Agostino Bassi first isolated the fungal pathogenic agent of the white muscardine in insects (later named Beauveria bassiana in his honor), and Ilya Mechnikov cultivated Metarhizium anisopliae as a first approach to use fungi as pest control agents, many other entomopathogenic fungi have been studied over the last two centuries [...] Full article

17 pages, 3621 KiB

Open AccessArticle

A Phylogenetic and Taxonomic Revision of Discula theae-sinensis, the Causal Agents of Anthracnose on Camellia sinensis

by Meijun Guo, Shiyi Zhao, Yue Gao, Xiaoye Shen and Chenglin Hou

J. Fungi 2024, 10(2), 141; https://doi.org/10.3390/jof10020141 - 9 Feb 2024

Cited by 1 | Viewed by 1498

Abstract

Tea (Camellia sinensis (L.) Kuntze) is one of the most important economic plants in China, and has many benefits for human health. Anthracnose is one of the most serious diseases of tea in China, and control of the fungus is important since [...] Read more.

Tea (Camellia sinensis (L.) Kuntze) is one of the most important economic plants in China, and has many benefits for human health. Anthracnose is one of the most serious diseases of tea in China, and control of the fungus is important since most Chinese cultivars are susceptible to it. The agent of tea anthracnose was initially described as Gloeosporium theae-sinensis I. Miyake in Japan, which was later transferred to Discula, but this taxonomic position remains problematic. To shed light on these taxonomic and phylogenetic issues, the tea anthracnose pathogens were re-studied. Combining the morphological characteristics and a multigene phylogenetic analysis of nrITS, nrLSU, rpb2, and tef1 sequence data, a new genus Sinodiscula was proposed to accommodate the causal fungi of tea anthracnose, including a new species Sinodiscula camellicola and a new combination Sinodiscula theae-sinensis. Furthermore, the pathogenicity of the pathogens was determined according to Koch’s postulates. This study thoroughly resolves the long-standing taxonomic and phylogenetic problems of the tea anthracnose pathogens. Full article

(This article belongs to the Special Issue Plant Pathogenic Fungi: Taxonomy, Phylogeny and Morphology)

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19 pages, 4963 KiB

Open AccessArticle

Transcriptome Analysis Reveals Mycelial and Fruiting Responses to Lithium Chloride in Coprinopsis cinerea

by Po-Lam Chan, Hoi-Shan Kwan, Yichun Xie, Ka-Hing Wong and Jinhui Chang

J. Fungi 2024, 10(2), 140; https://doi.org/10.3390/jof10020140 - 9 Feb 2024

Viewed by 1505

Abstract

Lithium chloride (LiCl) has been used in signalling and molecular studies of animals, plants, and yeast. However, information on its roles in basidiomycetous fungi is still limited. In this study, we used RNA-Seq to study the effects of LiCl on Coprinopsis cinerea. [...] Read more.

Lithium chloride (LiCl) has been used in signalling and molecular studies of animals, plants, and yeast. However, information on its roles in basidiomycetous fungi is still limited. In this study, we used RNA-Seq to study the effects of LiCl on Coprinopsis cinerea. LiCl enhanced mycelial growth and inhibited fruiting body formation in C. cinerea. RNA-Seq of the LiCl-treated C. cinerea resulted in a total of 14,128 genes. There were 1199 differentially expressed genes (DEGs) between the LiCl-treated samples and control samples in the mycelium stage (the first time point), and 1391 DEGs were detected when the control samples were forming hyphal knots while the treated samples were still in the mycelium (the second time point). Pathway enrichment analysis of the DEGs revealed a significant association between enhanced mycelium growth in the LiCl-treated C. cinerea and metabolic pathways. In addition, the DEGs involved in cellular process pathways, including “cell cycle-yeast” and “meiosis-yeast”, were identified in suppressed C. cinerea fruiting body formation by LiCl under favourable environmental conditions. As LiCl can predominantly inhibit the activity of glycogen synthase kinase3 (GSK3), our findings suggest that LiCl affects the expression of genes involved in fruiting body initiation and cellular processes by inhibiting GSK3 activity which is essential for fruiting body formation. Full article

(This article belongs to the Special Issue Molecular Genetics and Genomics of Mushroom-Forming Fungi)

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12 pages, 3616 KiB

Open AccessArticle

Morphology and Phylogeny Reveal Three New Species of Cytospora Associated with Tree Cankers in China

by Shuo Wang, Ning Jiang and Rong Ma

J. Fungi 2024, 10(2), 139; https://doi.org/10.3390/jof10020139 - 9 Feb 2024

Cited by 4 | Viewed by 1734

Abstract

Cytospora (Cytosporaceae, Diaporthales) is a fungal genus that usually inhabits plants as endophytes, saprobes, as well as pathogens. Species of this genus are characterized by possessing allantoid hyaline conidia and ascospores. Samples with typical Cytospora canker symptoms on Prunus davidiana, P. padus and [...] Read more.

Cytospora (Cytosporaceae, Diaporthales) is a fungal genus that usually inhabits plants as endophytes, saprobes, as well as pathogens. Species of this genus are characterized by possessing allantoid hyaline conidia and ascospores. Samples with typical Cytospora canker symptoms on Prunus davidiana, P. padus and Salix sp. were collected in Tibet and Xinjiang, China. Species were identified using both morphological and molecular approaches of combined loci of internal transcribed spacer region rDNA (ITS), the partial actin (act) region, RNA polymerase II second largest subunit (rpb2), the translation elongation factor 1-alpha (tef1) gene and the partial be-ta-tubulin (tub2) gene. Six isolates in the present study formed three distinct clades from previously known species. Cytospora hejingensis sp. nov. from Salix sp., C. jilongensis sp. nov. from P. davidiana and C. kunsensis from P. padus were proposed herein. The current study improves the understanding of species concept in Cytospora. Full article

(This article belongs to the Special Issue Plant Pathogenic Fungi: Taxonomy, Phylogeny and Morphology)

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18 pages, 3646 KiB

Open AccessArticle

Streptomyces spp. Strains as Potential Biological Control Agents against Verticillium Wilt of Olive

by Miriam Díaz-Díaz, Begoña I. Antón-Domínguez, María Carmen Raya, Alexander Bernal-Cabrera, Ricardo Medina-Marrero, Antonio Trapero and Carlos Agustí-Brisach

J. Fungi 2024, 10(2), 138; https://doi.org/10.3390/jof10020138 - 8 Feb 2024

Cited by 1 | Viewed by 1894

Abstract

Verticillium wilt of olive (VWO) caused by Verticillium dahliae is considered a major olive (Olea europaea) disease in Mediterranean-type climate regions. The lack of effective chemical products against VWO makes it necessary to search for alternatives such as biological control. The [...] Read more.

Verticillium wilt of olive (VWO) caused by Verticillium dahliae is considered a major olive (Olea europaea) disease in Mediterranean-type climate regions. The lack of effective chemical products against VWO makes it necessary to search for alternatives such as biological control. The main goal of this study was to evaluate the effect of six Streptomyces spp. strains as biological control agents (BCAs) against VWO. All of them were molecularly characterized by sequencing 16S or 23S rRNA genes and via phylogenetic analysis. Their effect was evaluated in vitro on the mycelial growth of V. dahliae (isolates V004 and V323) and on microsclerotia (MS) viability using naturally infested soils. Bioassays in olive plants inoculated with V. dahliae were also conducted to evaluate their effect against disease progress. In all the experiments, the reference BCAs Fusarium oxysporum FO12 and Aureobasidium pullulans AP08 were included for comparative purposes. The six strains were identified as Streptomyces spp., and they were considered as potential new species. All the BCAs, including Streptomyces strains, showed a significant effect on mycelial growth inhibition for both V. dahliae isolates compared to the positive control, with FO12 being the most effective, followed by AP08, while the Streptomyces spp. strains showed an intermediate effect. All the BCAs tested also showed a significant effect on the inhibition of germination of V. dahliae MS compared to the untreated control, with FO12 being the most effective treatment. Irrigation treatments with Streptomyces strain CBQ-EBa-21 or FO12 were significantly more effective in reducing disease severity and disease progress in olive plants inoculated with V. dahliae compared to the remaining treatments. This study represents the first approach to elucidating the potential effect of Streptomyces strains against VWO. Full article

(This article belongs to the Special Issue Diagnosis of Plant Pathogenic Fungi and Oomycetes and Plant Breeding for Disease Resistance, 3rd Edition)

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13 pages, 2919 KiB

Open AccessTechnical Note

Establishment of an Efficient Genetic Transformation System in Sanghuangporus baumii

by Xutong Wang, Mandi Wang, Jian Sun, Xiaolei Qu, Shixin Wang and Tingting Sun

J. Fungi 2024, 10(2), 137; https://doi.org/10.3390/jof10020137 - 8 Feb 2024

Viewed by 1575

Abstract

(1) Background: Sanghuangporus baumii, a valuable medicinal fungus, has limited studies on its gene function due to the lack of a genetic transformation system. (2) Methods: This study aimed to establish an efficient Agrobacterium tumefaciens-mediated transformation (ATMT) system for S. baumii. [...] Read more.

(1) Background: Sanghuangporus baumii, a valuable medicinal fungus, has limited studies on its gene function due to the lack of a genetic transformation system. (2) Methods: This study aimed to establish an efficient Agrobacterium tumefaciens-mediated transformation (ATMT) system for S. baumii. This study involved cloning the promoter (glyceraldehyde-3-phosphate dehydrogenase, gpd) of S. baumii, reconstructing the transformation vector, optimizing the treatment of receptor tissues, and inventing a new method for screening positive transformants. (3) Results: The established ATMT system involved replacing the CaMV35S promoter of pCAMBIA-1301 with the gpd promoter of S. baumii to construct the pCAMBIA-SH-gpd transformation vector. The vectors were then transferred to A. tumefaciens (EHA105) for infection. This study found that the transformation efficiency was higher in the infection using pCAMBIA-SH-gpd vectors than using pCAMBIA-1301 vectors. The mycelia of S. baumii were homogenized for 20 s and collected as the genetic transformation receptor. After 20 min of co-culture and 48 h of incubation in 15 mL PDL medium at 25 °C, new colonies grew. (4) Conclusions: These colonies were transferred to PDA medium (hygromycin 4 μg/mL, cefotaxime 300 μg/mL), and the transformation efficiency was determined to be 33.7% using PCR. Full article

(This article belongs to the Section Fungal Genomics, Genetics and Molecular Biology)

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19 pages, 3683 KiB

Open AccessArticle

Isolation and Identification of Acer truncatum Endophytic Fungus Talaromyces verruculosus and Evaluation of Its Effects on Insoluble Phosphorus Absorption Capacity and Growth of Cucumber Seedlings

by Qingpan Zeng, Jiawei Dong, Xiaoru Lin, Xiaofu Zhou and Hongwei Xu

J. Fungi 2024, 10(2), 136; https://doi.org/10.3390/jof10020136 - 8 Feb 2024

Cited by 4 | Viewed by 1788

Abstract

The symbiosis between endophytic fungi and plants can promote the absorption of potassium, nitrogen, phosphorus, and other nutrients by plants. Phosphorus is one of the indispensable nutrient elements for plant growth and development. However, the content of available phosphorus in soil is very [...] Read more.

The symbiosis between endophytic fungi and plants can promote the absorption of potassium, nitrogen, phosphorus, and other nutrients by plants. Phosphorus is one of the indispensable nutrient elements for plant growth and development. However, the content of available phosphorus in soil is very low, which limits the growth of plants. Phosphorus-soluble microorganisms can improve the utilization rate of insoluble phosphorus. In this study, Talaromyces verruculosus (T. verruculosus), a potential phosphorus-soluble fungus, was isolated from Acer truncatum, a plant with strong stress resistance, and its phosphorus-soluble ability in relation to cucumber seedlings under different treatment conditions was determined. In addition, the morphological, physiological, and biochemical indexes of the cucumber seedlings were assessed. The results show that T. verruculosus could solubilize tricalcium phosphate (TCP) and lecithin, and the solubilization effect of lecithin was higher than that of TCP. After the application of T. verruclosus, the leaf photosynthetic index increased significantly. The photosynthetic system damage caused by low phosphorus stress was alleviated, and the root morphological indexes of cucumber seedlings were increased. The plant height, stem diameter, and leaf area of cucumber seedlings treated with T. verruculosus were also significantly higher than those without treatment. Therefore, it was shown that T. verruculosus is a beneficial endophytic fungus that can promote plant growth and improve plant stress resistance. This study will provide a useful reference for further research on endophytic fungi to promote growth and improve plant stress resistance. Full article

(This article belongs to the Special Issue Fungal Endophytes in Agriculture)

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17 pages, 11914 KiB

Open AccessArticle

The Transcription Factor SsZNC1 Mediates Virulence, Sclerotial Development, and Osmotic Stress Response in Sclerotinia sclerotiorum

by Yongkun Huang, Zhima Zhaxi, Yanping Fu, Jiatao Xie, Tao Chen, Bo Li, Xiao Yu, Yang Lin, Daohong Jiang and Jiasen Cheng

J. Fungi 2024, 10(2), 135; https://doi.org/10.3390/jof10020135 - 8 Feb 2024

Cited by 1 | Viewed by 1657

Abstract

Sclerotinia sclerotiorum is a fungal pathogen with a broad range of hosts, which can cause diseases and pose a great threat to many crops. Fungal-specific Zn₂Cys₆ transcription factors (TFs) constitute a large family prevalent among plant pathogens. However, the function [...] Read more.

Sclerotinia sclerotiorum is a fungal pathogen with a broad range of hosts, which can cause diseases and pose a great threat to many crops. Fungal-specific Zn₂Cys₆ transcription factors (TFs) constitute a large family prevalent among plant pathogens. However, the function of Zn₂Cys₆ TFs remains largely unknown. In this study, we identified and characterized SsZNC1, a Zn₂Cys₆ TF in S. sclerotiorum, which is involved in virulence, sclerotial development, and osmotic stress response. The expression of SsZNC1 was significantly up-regulated in the early stages of S. sclerotiorum infection on Arabidopsis leaves. The target deletion of SsZNC1 resulted in reduced virulence on Arabidopsis and oilseed rape. In addition, sclerotial development ability and growth ability under hyperosmotic conditions of SsZNC1 knockout transformants were reduced. A transcriptomic analysis unveiled its regulatory role in key cellular functions, including cellulose catabolic process, methyltransferase activity, and virulence, etc. Together, our results indicated that SsZNC1, a core regulatory gene involved in virulence, sclerotial development and stress response, provides new insight into the transcription regulation and pathogenesis of S. sclerotiorum. Full article

(This article belongs to the Special Issue Fungal Plant Pathogens)

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17 pages, 4983 KiB

Open AccessArticle

Combined Proteomic and Metabolomic Analyses Reveal the Comprehensive Regulation of Stropharia rugosoannulata Mycelia Exposed to Cadmium Stress

by Qin Dong, Mingjie Chen, Changxia Yu, Yaru Zhang, Lei Zha, Pattana Kakumyan, Huanling Yang and Yan Zhao

J. Fungi 2024, 10(2), 134; https://doi.org/10.3390/jof10020134 - 7 Feb 2024

Viewed by 1696

Abstract

The potential of Stropharia rugosoannulata as a microbial remediation material for cadmium (Cd)-contaminated soil lies in its capacity to absorb and accumulate Cd in its mycelia. This study utilized the TMT and LC−MS techniques to conduct integrated proteomic and metabolomic analyses with the [...] Read more.

The potential of Stropharia rugosoannulata as a microbial remediation material for cadmium (Cd)-contaminated soil lies in its capacity to absorb and accumulate Cd in its mycelia. This study utilized the TMT and LC−MS techniques to conduct integrated proteomic and metabolomic analyses with the aim of investigating the mycelial response mechanisms of S. rugosoannulata under low- and high-Cd stresses. The results revealed that mycelia employed a proactive defense mechanism to maintain their physiological functions, leading to reduced sensitivity to low-Cd stress. The ability of mycelia to withstand high levels of Cd stress was influenced primarily by the comprehensive regulation of six metabolic pathways, which led to a harmonious balance between nitrogen and carbohydrate metabolism and to reductions in oxidative stress and growth inhibition caused by Cd. The results provide valuable insights into the molecular mechanisms involved in the response of S. rugosoannulata mycelia to Cd stress. Full article

(This article belongs to the Special Issue Fungal-Related Proteomics in Biotechnology and Health)

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15 pages, 4661 KiB

Open AccessArticle

The Effects of Mycovirus BmPV36 on the Cell Structure and Transcription of Bipolaris maydis

by Yajiao Wang, Qiusheng Li, Yuxing Wu, Sen Han, Ying Xiao and Lingxiao Kong

J. Fungi 2024, 10(2), 133; https://doi.org/10.3390/jof10020133 - 6 Feb 2024

Cited by 2 | Viewed by 1574

Abstract

Bipolaris maydis partitivirus 36 (BmPV36) is a mycovirus that can significantly reduce the virulence of the host Bipolaris maydis, but its hypovirulence mechanism is not clear. To investigate the response of B. maydis to BmPV36, the effects of BmPV36 on host cell [...] Read more.

Bipolaris maydis partitivirus 36 (BmPV36) is a mycovirus that can significantly reduce the virulence of the host Bipolaris maydis, but its hypovirulence mechanism is not clear. To investigate the response of B. maydis to BmPV36, the effects of BmPV36 on host cell structure and gene expression were studied via transmission electron microscopy and transcriptome sequencing using BmPV36-carrying and virus-free mycelium on the second and fifth culture. The results of transmission electron microscopy showed that the cell wall microfibrils of B. maydis were shortened, the cell membrane was broken, and membrane-bound vesicles and vacuoles appeared in the cells after carrying BmPV36. Transcriptome sequencing results showed that after carrying BmPV36, B. maydis membrane-related genes were significantly up-regulated, but membrane transport-related genes were significantly down-regulated. Genes related to carbohydrate macromolecule polysaccharide metabolic and catabolic processes were significantly down-regulated, as were genes related to the synthesis of toxins and cell wall degrading enzymes. Therefore, we speculated that BmPV36 reduces the virulence of B. maydis by destroying the host’s cell structure, inhibiting the synthesis of toxins and cell wall degrading enzymes, and reducing cell metabolism. Gaining insights into the hypovirulence mechanism of mycoviruses will provide environmentally friendly strategies for the control of fungal diseases. Full article

(This article belongs to the Special Issue Mycoviruses: Emerging Investigations on Virus-Fungal Host Interaction)

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J. Fungi, Volume 10, Issue 2 (February 2024) – 74 articles

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